Refrigeration



Feb. 27, 1940- H. M. ULLSTRAND REFRIGERATION Filed April 7, 1938 Patented Feb. 27, 1940 PATENT OFFICE REFRIGERATION Hugo M. Ullstrand, Evansville, Ind., assignor to Servel, Inc., New York, N. Y., a corporation of Delaware Application April 7, 1938; Serial No. 200,571

4 Claims.

My invention relates to an absorption type refrigeration system and it is an object of the invention to provide a system of this type having greater efiiciency.

Fig. 1 of the drawing shows more or less diagrammatically an absorption refrigeration system of a type making use of an auxiliarypressure equalizing fluid. Fig. 2 is a detail sectional view on line 2-2 in Fig. 1.

A generator [0 comprises a horizontal portion divided into chambers II and I2 and an upright portion or standpipe l3. The lower end of standpipe I3 is connected to chamber l2. Chamber II is provided with a dome M. A thermosyphon or ,vapor liquid lift conduit I5 is connected from chamber II to the upper part of standpipe l3. The lower end of conduit 15 extends downward through the dome l4 into chamber H. The generator is heated by a gas burner l6 arranged so that the flame is projected into the lower end of a flue 11 which extends through the horizontal portion of the generator..

An absorber l8 comprises a pipe coil provided with heat transfer 'fins for cooling by air; A

condenser I9. also comprises a pipe coil provided with heat radiation fins. evaporator 21! comprises a pipe coil located ln'a thermally insulated refrigerator compartment ll...

Thef upp r end, of evaporator is connected exchanger 24,, and a conduitlfi to the lower end of, absorber'lt, and the upper or; a vessel 2,8,. referred to as an absorber'sump or'vessel. The uppe p r s! a s ber swnnected by a on duitf zflf'outerfpas'sage of/th'e gas heatex-I i c ansve d a uit 2a t th lp ere idf t 5 upper partof vessel 26. Thelowerpartbfab;

" so'rbe'r vessel ms connected by ccnduit 3.5, midj-Z die passage of heat BXQhflng'ei '3.l l'."a conduit 38.11. a" vessel 1.1.8.116. a 9 Quit :0? ham er t- 3 1?! "5 he P933 iiidf i i d it 3.

' pm or w amara 1 "The upper end of standpipe [3, is connected to the upper endf f co ideliser 19 by a conduit 40. outside passage 41 of heatexchanger 31!, and condult 4,4. The upperend'ofvessel 3,1 is connected shown, responsive to a t b th urn cens s e nu si n dffammonis by a conduit 43 to conduit 40. The lower end of outside passage 4| of heat exchanger 30 is connected to theupper part of vessel 31 by a conduit 44, a chamber 46, and a thermosyphon or vapor liquid lift conduit 45. The lower end of conduit 5 45 projects downward into chamber 46. Chamber 46 is formed on the outside of chamber H of the generator I 0, as better seen in Fig. 2.

The lower end of condenser I9 is connected by a conduit 48 to the upper end of evaporator 20;10

The lower end of condenser 19 is also connected by a conduit 41, a gas accumulation vessel 49, and a conduit 50 to the inner passage 23 of gas heat exchanger 24.

The system contains a suitable refrigerant such 15 as ammonia, a liquid absorbent such as water, and an auxiliary pressure equalizing fluid such as hydrogen. As shown, the absorber l8 and condenser I9 are directly cooled by air. The absorber and condenser may be otherwise cooled, as by 20 circulating water or by vaporization-condensation heat transfer circuit. Instead of a gas burner l6, other suitable means may be used for heating the generator, such as an electric heating element or 4 a liquid fuel burner. The heater for the gener- 25 atornnay be'cqntrolledj by 'a-thermostat'. nod p v fmperat re o di l n fectedby'the evaporator'lll." In operat on," hea appl 0 the gen rat r,

pa imt f qluti in: Vapo l e. i nm ha nber; lla cumu 415.- w m: r a le iew 0. liq i hr u h hi enqu artbe ni 'svnhon' r vapo" liquid lift action"into-theupper' e n p 'j 1 apor chamber 12 a d-smmipipe in P 1 th tander. ,4 nowsnomtne per end of standpi'pe lijthrough er' I. e lni Vapor n enses t iquid in m denser 1:91. an i'fldw t rough c ndo, 48 into. the uppeien'd oi evaporatorzq. Liquid'amn'ionia" flows. downward in" evaporator *myevaporating 45 and difiusing into hydrogen, producing 'a reirig crating effect. The resulting mixture of, hydroweak solution flows downward in absorber I8 I in total pressure in the system under high room temperature conditions, as known.

Weak solution flowing through inner passage 33of heat exchanger 30 gives up heat to strong solution flowing in the opposite direction in the middle passage 36. Vapor from the generator flowing inoutside passage 4| of the heat exchanger 30 also gives up heat to strong solution flowing in the opposite direction in middle passage 36.

-Transfer of heat from the vapor is accompanied by condensation in the outside passage 4|. This condensation effects removal of water vapor accompanying ammonia vapor from the generator and is referred to as rectification. The condensate flows downward in the outside passage 4| into conduit 44 and chamber 46. Chamber 46 is heated indirectly, transfer of heat thereto being through liquid contained in chamber H of the generator. Vapor which is formed in chamber 46 by heating of condensate therein accumulates in the upper part of chamber 46 and causes upward flow of liquid through conduit by thermosyphon or vapor lift action whereby condensate from the outside passage 4| of the heat exchanger 30 is raised into vessel 31. The condensate joins rich solution in vessel 31 and is returned therewith through conduit 38 to the generator chamber Circulation of the gas through and between the evaporator 20 and absorber I8 is caused in a known manner by difference in specific weights of the rich and weak gas. The described flow of weak solution from the generator to the absorber occurs by gravity. The surface level of liquid in standpipe |3 is high enough so that liquid overflows from the upper end of conduit 34 into the upper end of absorber l8. .The described flow of strong solution takes place by thermosyphon or vapor lift action in conduit l5 Strong solution-stands in absorber vessel Y26 and vessel 3'! at substantially the same levels which aresufliciently' above the lower endof conduit l5 so that the. column of vapor and liquid-formed in conduit Enriched absorption liquid sary to raise the condensate formed in outside passage 4| above the surface level of liquid in the system to keep the passage 4| free for flow of vapor and to return the condensate into the liquid circuit. This is accomplished by the auxiliary vapor lift or thermosyphon provided by conduit 44, chamber 46, and conduit 45 through which condensate is raised into vessel 31 above the surface level of strong solution therein.

Various changes and modifications may be made within the scope of the invention as set forth in the following claims.

What is claimed is:

l. A refrigeration system containing refrigerant and liquid absorbent for the refrigerant, and having a generator, means for heating said generator, an absorber, a rectifier, a thermosyphon or vapor liquid lift for causing circulation of fluid between said generator and absorber, and a second thermosyphon or vapor liquid lift for causing circulation of fluid between said generator and rectifier, said second thermosyphon or vapor liquid lift being arranged to receive heat by transfer through liquid in the system. 4

2. A refrigeration system as set forth in claim 1 also having a liquid heat exchanger connected between said generator and absorber, said rectifier being in heat exchange relation with said heat exchanger.

3. A refrigeration system as set forth in claim 1 in which heat from said generator heating means. is transferred to said second thermosyphon or vapor liquid lift by transfer through liquid in said generator.

4. In an absorption refrigeration system, having a circuit for absorption liquid, the combination with a rectifier of a heated vessel and a, rising conduit having its lower end projecting into said vessel, said vessel being heated by transfer thereto of heat through liquid in the system, said rectifier being above said vessel and connected thereto for flow of liquid condensate from the rectifier into said heated vessel, said combination being connectedin said system-so thatsaid rectifier is locat'ed below the upper level of absorption liquidinsaid'circuit and liquid and.

vapor rise through said conduit an'd'return to their respective pathsof flow in the system HUGO M- U'LLS' irm in 

